Due to the increasing energy demands, offshore oil and gas production is moving into deeper waters. For ensuring an efficient and secure production, processing facilities are being installed on the ocean floor. Such subsea installations can comprise a range of components, including pumps, compressors and the like as well as a power grid for operating them. The power grid may for example comprise a subsea transformer, subsea switch gear and subsea variable speed drives.
Components of such subsea installation can comprise electronic equipment that can be monitored and/or controlled from a topside installation, such as a topside control system which may be located on a fixed or floating vessel, for example a ship or platform, or may be based on shore. The subsea installation can for example comprise one or more subsea control modules, which can receive commands from the topside installation and which can transmit information to the topside installation, such as sensor readings or the like, and which may further communicate with each other. In other configurations, a number of sensors may be interrogated from the topside installation, for example through a subsea communication unit.
An existing subsea communication infrastructure is generally based on a topology in which the equipment installed subsea communicates on a multidrop bus with one unit that is installed topside. In such topology, the topside unit may request certain data, or may send commands to one or more individual subsea units, for example using a round robin scheme. In such communication topologies, all subsea units require the same type of electrical data interface and are required to use the same protocol for data transmission. Further, all units connected to the multidrop bus are required to operate with the same data transmission performance. In a practical implementation, this means that the oldest or slowest unit dictates the bandwidth limitations for all connected units.
The data transmission capability of such multidrop system is accordingly relatively low. Furthermore, since all units are required to adhere to the multidrop data communication, upgrading of such system is difficult and all units would need to be replaced for the introduction of a faster data transmission technology.
Accordingly, it is desirable to improve the communication between subsea units and topside units, and in particular to be capable of increasing the bandwidth and facilitating the upgrading of such communication system.